Digital beamforming fin antenna assembly

Abstract

An antenna assembly includes a plurality of active antenna elements disposed in a first linear array along a reference line and equidistant from each adjacent antenna element by a first linear distance, and a plurality of passive antenna elements disposed in a second linear array extending parallel to the reference line such that each passive antenna element is a second linear distance away from a corresponding one of the active antenna elements. The antenna assembly includes or is operably coupled to a phase control module configured to apply selected phase fronts to selected ones of the antenna elements to generate constructive and destructive interference patterns to define a directive beam in a desired direction in a range between about 0 and 180 degrees relative to the reference line.

What is claimed is: 
     
       1. An antenna assembly comprising:
 a plurality of active antenna elements disposed in a first linear array along a reference line and equidistant from each adjacent antenna element by a first linear distance; 
 a plurality of passive antenna elements disposed in a second linear array extending parallel to the reference line such that each passive antenna element is a second linear distance away from a corresponding one of the active antenna elements; and 
 a ground plane at which the active and passive antenna elements are mounted such that the active and passive antenna elements each extend substantially perpendicularly away from the ground plane and parallel to each other, 
 wherein the antenna assembly includes or is operably coupled to a phase control module configured to apply selected phase fronts to selected ones of the antenna elements to generate constructive and destructive interference patterns to define a directive beam in a desired direction in a range between about 0 and 180 degrees relative to the reference line, and 
 wherein the ground plane is formed at an underside of an aircraft wing or fuselage. 
 
     
     
       2. The antenna assembly of  claim 1 , wherein a number of the active antenna elements and a number of the passive antenna elements is eight. 
     
     
       3. The antenna assembly of  claim 2 , wherein the second linear distance is about equal to a quarter wavelength of a frequency of operation of the antenna assembly, and
 wherein the first linear distance is less than or equal to the second linear distance. 
 
     
     
       4. The antenna assembly of  claim 3 , wherein the frequency of operation is about 2.4 GHz, and the first and second linear distances are each about 1.5 inches. 
     
     
       5. The antenna assembly of  claim 1 , wherein a radome houses the antenna elements, the radome being operably coupled to the aircraft wing or fuselage. 
     
     
       6. The antenna assembly of  claim 5 , wherein the radome has a width of less than about 2 inches and a height of less than about 1.5 inches,
 wherein the radome has a length of less than about 8.5 inches, 
 and wherein the ground plane is at least 4 feet in diameter. 
 
     
     
       7. The antenna assembly of  claim 6 , wherein the antenna assembly comprises a fin antenna having a length dimension that is at least four times larger than a height dimension and width dimension of the fin antenna. 
     
     
       8. The antenna assembly of  claim 1 , wherein the phase control module is disposed at a remote radio head provided between the antenna assembly and a beamforming control module, the beamforming control module being configured to provide instructions to the phase control module for generating the selected phase fronts. 
     
     
       9. The antenna assembly of  claim 8 , wherein the phase control module is configured to apply no phase adjustment to a selected active antenna element, and apply a selected phase adjustment to at least one adjacent active antenna element to the selected active antenna element to form a resultant directive beam. 
     
     
       10. The antenna assembly of  claim 9 , wherein, responsive to operation of the phase control module, the antenna assembly is configurable to steer a directive beam having a beamwidth of about 39 degrees in the range between about 0 to 180 degrees in azimuth with a fixed beamwidth in elevation. 
     
     
       11. The antenna assembly of  claim 10 , wherein the antenna assembly is configured to be disposed on an aircraft, and wherein the fixed beamwidth in elevation is directed toward the horizon, and
 wherein the fixed beamwidth is about 70 degrees in elevation. 
 
     
     
       12. The antenna assembly of  claim 1 , further comprising a second plurality of active antenna elements disposed in a third linear array along a second reference line extending parallel to the first reference line; and
 a second plurality of passive antenna elements disposed adjacent the plurality of passive antenna elements in a fourth linear array extending parallel to the second reference line such that each passive antenna element of the second plurality of passive antenna elements is adjacent to a corresponding one of the second plurality of active antenna elements to define a dual fin antenna.